
//***********************************************
//
//      Filename: homework2.java
//
//        Author: wwb
//        Mails: 1274860621@qq.com
//        Create: 2018-04-11 16:16:07
// Last Modified: 2018-04-11 16:16:07
//***********************************************
import java.util.Scanner;
public class homework2 {
    public static void main(String[] args) {
        int count;
        int sum = 1;
        int count1 = 1;
        Scanner scan = new Scanner(System.in);
        System.out.println("please enter a number: ");
        count = scan.nextInt();
        while (count1 <count) {
            count1++;
            sum *= count1;

        }
        System.out.println(sum);
    }
}
